Sioux Falls, South Dakota – Residents across South Dakota, Iowa, and Minnesota should prepare for dangerous heat conditions starting Friday and lasting through Sunday. The combination of high temperatures and humidity will push heat index values into the triple digits, posing a significant risk of heat-related illnesses.
According to the US National Weather Service Sioux Falls, an early summer heatwave will bring a Major Heat Risk (Level 3 of 4) to widespread areas, with isolated pockets of Extreme Heat Risk. Peak heat index values on Saturday are expected to reach as high as 107 degrees in Sioux Falls, 108 in Sioux City, and 106 in Worthington, Minnesota. Brookings, South Dakota, could see an extreme heat index of 105.
Outdoor activities should be avoided, especially during the warmest parts of the day. Those without effective cooling or hydration will face the highest risk. Residents should drink plenty of water, wear lightweight and light-colored clothing, and seek air-conditioned environments. Fans and open windows will not offer enough relief during this period.
A cold front is expected to move across the area late Sunday into Sunday night, breaking the heatwave. Until then, heat advisories and warnings will remain in effect.
